Transition state volumes and solvolysis mechanisms

1970 ◽  
Vol 48 (13) ◽  
pp. 2025-2030 ◽  
Author(s):  
MOYRA J. Mackinnon ◽  
A. B. Lateef ◽  
J. B. Hyne
Keyword(s):  
Transition State ◽  
Benzyl Chloride ◽  
Activation Volume ◽  
Solvent Composition ◽  
Binary Solvent ◽  
Partial Molal Volume ◽  
Butyl Chloride ◽  
Molal Volume ◽  
Reaction Type

The transition state partial molal volume behavior, [Formula: see text] as a function of binary solvent composition was obtained for three reactions by dissection of the activation volume, ΔV*, into initial and transition state components: [Formula: see text] The solvolyses of t-butyl chloride, benzyl chloride, and p-chlorobenzyl chloride represented a gradation of reaction type between SN1 and SN2 and the transition state partial molal volume behavior was found to be distinctly different in each case and in agreement with the mechanistic classification of these reactions.

The pressure dependence of benzyl chloride solvolysis in aqueous acetone and aqueous dimethylsulfoxide

1970 ◽  
Vol 48 (16) ◽  
pp. 2494-2499 ◽  
Author(s):  
Digby D. Macdonald ◽  
J. B. Hyne
Keyword(s):  
Transition State ◽  
Benzyl Chloride ◽  
Activation Volume ◽  
Aqueous Acetone ◽  
Solvent Composition ◽  
Pressure Data ◽  
Initial State ◽  
First Order ◽  
Solvent Systems ◽  
Aqueous Dimethylsulfoxide

First-order rate constants for the solvolysis of benzyl chloride in a series of aqueous acetone and aqueous dimethylsulfoxide (DMSO) mixtures at 50.100 °C and at various pressures in the range 1–4083 atm are reported. Volume of activation, calculated from the rate/pressure data, is found to exhibit extremum behavior with varying solvent composition in both solvent systems. The activation volumes are dissected into their initial state and transition state contributions by determining the "instantaneous" volumes of solution of benzyl chloride in the solvent systems. The contributions of both the initial state and the transition state to the behavior of the activation volume as a function of solvent composition are discussed.

Anilinium chloride as a model for the transition state for benzyl chloride solvolysis

1969 ◽  
Vol 47 (8) ◽  
pp. 1437-1439 ◽  
Author(s):  
Ikchoon Lee ◽  
J. B. Hyne
Keyword(s):  
Transition State ◽  
Benzyl Chloride ◽  
Composition Dependence ◽  
Structural Model ◽  
Activation Process ◽  
Electrostatic Model ◽  
Partial Molal Volume ◽  
Tetraethylammonium Chloride ◽  
Molal Volume ◽  
Alkyl Ammonium

The solvent composition dependence of the partial molal volume of the transition state of benzyl chloride solvolysing in water–ethanol mixtures is compared with that of anilinium chloride and a number of quaternary alkyl ammonium chlorides. It is concluded that anilinium chloride is not a good electrostatic model for the benzyl chloride transition state even though it may be a fair structural model. The partial molal volume of tetraethylammonium chloride is very similar to that of the transition state suggesting that charge development in the activation process is far from being fully ionic.

Partial molal volume behavior of tetraalkylammonium chlorides in aqueous acetone and aqueous dimethylsulfoxide

1970 ◽  
Vol 48 (15) ◽  
pp. 2416-2422 ◽  
Author(s):  
Digby D. Macdonald ◽  
J. B. Hyne
Keyword(s):  
Molecular Weight ◽  
Aqueous Acetone ◽  
Solvent Composition ◽  
Partial Molal Volume ◽  
Volume Data ◽  
Molal Volume ◽  
Partial Molal Volumes ◽  
Molal Volumes ◽  
Aqueous Dimethylsulfoxide ◽  
Linear Expression

The partial molal volumes of a series of tetraalkylammonium chlorides in aqueous acetone and aqueous dimethylsulfoxide at 25.000 °C are reported as a function of solvent composition. It is shown that for each solvent composition the partial molal volume data are better represented by a quadratic in solute molecular weight than by the linear expression previously employed in similar studies. Extrapolation of molecular partial molal volumes to zero cation molecular weight has permitted evaluation of the partial molal volumes of the ions R4N+ and Cl−. The variation of molecular and ionic partial molal volume as a function of solvent composition is discussed.

Effect of Pressure on the Solvolysis of Dimethyl-t-butyl Sulfonium Iodide in Ethanol–Water Mixtures

1972 ◽  
Vol 50 (14) ◽  
pp. 2270-2275 ◽  
Author(s):  
Claude S. Davis ◽  
J. B. Hyne
Keyword(s):  
Reaction Mechanism ◽  
Transition State ◽  
Pressure Dependence ◽  
Composition Dependence ◽  
Partial Molal Volume ◽  
Molal Volume ◽  
Effect Of Pressure ◽  
Partial Molal Volumes ◽  
Molal Volumes

The pressure dependence of the rate of solvolysis of dimethyl-t-butyl sulfonium iodide has been studied in ethanol–water mixtures at 60.00 °C. Determination of the partial molal volume of the substrate ions has enabled the volumes of activation to be dissected into initial and transition state components. The solvent composition dependence of the partial molal volumes of the two states provides further details of the nature of the reaction mechanism.

Solvolysis of isopropyl bromide in ethanol–water mixtures. Dissection into initial state and transition state contributions

1976 ◽  
Vol 54 (24) ◽  
pp. 3944-3948 ◽  
Author(s):  
Wiendelt Drenth ◽  
Michael Cocivera
Keyword(s):  
Vapor Pressure ◽  
Transition State ◽  
Thermodynamic Parameters ◽  
Activation Parameters ◽  
Solvent Composition ◽  
Initial State ◽  
Partial Vapor Pressure ◽  
State Variation

Rates were determined for the solvolysis of isopropyl bromide in ethanol–water mixtures (20 to 80% by volume of ethanol) at 50 and 75 °C and the corresponding activation parameters calculated. From the partial vapor pressure of isopropyl bromide over the various solutions at 50 and 75 °C, the variations in its initial state thermodynamic parameters were calculated. Thus, the variation in the activation parameters with solvent composition could be analyzed in terms of initial and transition state contributions. The initial state variation dominates according to a unimolecular as well as to a bimolecular treatment of data.

scholarly journals INTERACTION STUDIES OF AMINO ACIDS IN AQUEOUS SODIUM BROMIDE SOLUTIONS AT DIFFERENT TEMPERATURE

2017 ◽  
Vol 5 (10) ◽  
pp. 160-167
Author(s):  
Yasmin Akhtar
Keyword(s):  
Amino Acids ◽  
Infinite Dilution ◽  
Adiabatic Compressibility ◽  
Sodium Bromide ◽  
Apparent Molal Volume ◽  
Partial Molal Volume ◽  
Molal Volume ◽  
Solvent Interactions ◽  
Aqueous Sodium ◽  
Bonding Effect

Densities, ultrasonic velocities and viscosities of L- Valine and L- Phenylalanine in aqueous sodium bromide (0.00, 0.025 and 0.05) m solutions have been determined experimentally at 308 and 313 K. The results obtained from density ultrasonic velocity and viscosity measurement have been used to calculate the apparent molal volume, фv, apparent molal, adiabatic compressibility ф Ks, partial molal volume ф0v at infinite dilution, partial molal adiabatic compressibility ф0Ks at infinite dilution, transfer volume ∆ф(tr), experimental slopes Sv and SKs,Falkenhagen coefficient A and  Jones-Dole B coefficient. The results are discussed in terms of the dehydration effect of the sodium bromide upon the amino acids and weak solute- solute and strong solute- solvent interactions. The properties of these amino acids in water and water + sodium bromide solution systems are discussed in terms of the charge, size and hydrogen bonding effect.

scholarly journals Study of Physical Properties for Sodium acetate with Water and Water - Acetone mixtures at Different Temperatures

2017 ◽  
Vol 27 (4) ◽  
Author(s):  
Ahmed Mohammed Abbas ◽  
Zainab Wajdi Ahmed ◽  
Alaa Fadhil Sulaiman ◽  
Issam AbdalKreem AbdalLatif
Keyword(s):  
Sodium Acetate ◽  
Apparent Molal Volume ◽  
Viscosity Data ◽  
Partial Molal Volume ◽  
Molal Volume ◽  
Solvent Interactions ◽  
Acetone Water ◽  
Thermodynamic Activation Parameter ◽  
Different Temperatures ◽  
Apparent Molal Compressibility

In this study binary and ternary solutions are prepared by using the sodium acetate concentrations (0.1, 0.125, 0.2, 0.25, 0.4, 0.5, 0.8, 1 M) in water and acetone –water mixtures .The important parameters such as apparent molal volume, the partial molal volume transfer,  apparent  molal compressibility, free energy of activation of viscous flow and thermodynamic activation parameter (enthalpy and entropy) determined of sodium acetate in water , 20%, 40% ,60% and 80% V/V acetone –water mixtures at 298.15K, 303.15K, and 308.15K from density and viscosity measurements espectively. The limiting apparent molal volumes and experimental slopes were derived from the Masson equation, have been interpreted in terms of solute–solvent and solute–solute interactions  respectively. The viscosity data were analyzed using theJones–Dole equation and the derived parameter B - coefficient has also been interpreted in terms of solute–solvent interactions in the solutions. 

Solvent-induced stresses in glassy polymer: Elastic model

1999 ◽  
Vol 14 (10) ◽  
pp. 4111-4118 ◽  
Author(s):  
Wei-Lung Wang ◽  
J. R. Chen ◽  
Sanboh Lee
Keyword(s):  
Mass Transport ◽  
Surface Concentration ◽  
Anomalous Transport ◽  
Initial Time ◽  
Elastic Model ◽  
Partial Molal Volume ◽  
Longitudinal Displacement ◽  
Linear Elasticity Theory ◽  
Molal Volume ◽  
Induced Stresses

The solvent-induced stresses in glassy polymers were investigated. The mass transport accounts for case I, case II, and anomalous transport. Case I transport is attributed to the concentration gradient, whereas case II transport is attributed to stress relaxation. Anomalous transport is the mixture of case I and case II. Both one-side and two-side mass transports with the boundary condition of constant surface concentration are considered. The stresses and longitudinal displacement arising from the mass transport are formulated based on the linear elasticity theory. The maximum stress is always located at the surface at the initial time. The stresses are a function of the partial molal volume, Young's modulus, and Poisson's ratio. From the longitudinal displacement data, the partial molal volume was determined.

Heat capacities and volumes of some non-electrolytes in N,N-dimethylformamide at 298.15 K

1987 ◽  
Vol 65 (12) ◽  
pp. 2810-2814 ◽  
Author(s):  
Henryk Piekarski
Keyword(s):  
Ethylene Glycol ◽  
Heat Capacities ◽  
Scaled Particle Theory ◽  
Partial Molal Volume ◽  
Cavity Formation ◽  
Particle Theory ◽  
Molal Volume ◽  
Analogous Data ◽  
Other Substances ◽  
Apparent Molal Heat Capacities

Heat capacities and densities of dilute solutions of formamide, acetone, tetrahydrofuran, ethylene glycol, 2-methoxyethanol, and 2-ethoxyethanol in N,N-dimethylformamide were determined at 298.15 K. Apparent molal heat capacities and volumes for these solutes in DMF were calculated and compared with the analogous data for other substances in DMF solution as well as with the data concerning solutions in methanol and water. Heat capacities of cavity formation (ΔCcav) in DMF were calculated on the basis of the Scaled Particle Theory. ΔCcav appeared to be linearly correlated with the standard partial molal volume of corresponding solutes in DMF. Similar dependences were also found for aqueous and methanolic solutions of the non-electrolytes.

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